Looking for help on QOS

Hello ALL!

Isn’t this stuff great!!?!

Well I am very new to this and I am very excited about Asterisk, PBXiaF and the whole technology.

I am looking for some guidance/support/help on setting up a reliable system in my small home office.

My original set up which I tested for a while:
Power Spec Intel Celeron D 3.3 w/ 1 GB Ram
On board NIC (10/100)
Linksys WRT54G Router with the QOS set to High on the physical port of the * box.
It was running TrixBox
Voice Pulse IAX trunks over Comcast Cable

I had a couple phones hooked up and it worked really good.

Then I went way on a trip and while gone the HDD failed… (and so it all begins)

While away (2 month biz trip) I spoke to the person who introduced me to * in depth. I ordered some new hardware in hopes to set up the my * system when I returned to be a good and reliable sustem for my business.

Shortly after I got back PBXiaF was released so I decided I would try that when I reloaded everything. I also figured it would be a good time to upgrade the network stuff.

So I set up PBXiaF on:
HP P4 2.6 G w/ 1.5G Ram
I installed a generic gig nic card (instead of on board 10/100)

( also changed the nic card and HDD on the PS box I was using before. I upgraded the pile of hubs and switches I had to:

Cat 6 cables (where Gig was supported)
Linksys SRW2016 Managed Switch
Linksys RV042 Router

And then the fun began…

I started having poor quality issues. It turns out that Comcast needs another node in my area (took them a cpl weeks to figure that out and replace all my new cable in office). I know that cable shares BW but in peak hours it dropped to 120k range.

So they tracked down the issue (keep in mind I am on a Static IP Commercial Line that at one time gave me good BW ~15mbps/~2mbps down max & ~5-6mbs/down ~768k/up min). Anyway… they could not resolve this until the week of 12/3/07. So with a month still ahead of me like this I ordered a DSL line from verizon.

Now the verizon line is in and I have all of the internet going through the cable and just the VoIP on the DSL.

I believe it is much better… but I dont think it is as good as it was before I made all they changes and upgrades. I seem to get some static and some of the audio breaks up (a little). The verizon line is a 3mbps/768k line.

So I have a few questions for some of the gurus out there…

A… Can something like using a cheap generic NIC card make a difference?

B… Does anyone successfully use one ISP for both a biz line and internet?

C… What suggestions does anyone have for setting up QOS so that a single ISP can be used and the call quality will still remain good even if other things are going on on the internet.

D… Does anyone know how to set up packet level QOS on a SRW2016 so I can go back to using one ISP once it is fixed? If not can anyone point me to someone or company who does?

If a mod feels this should be in a the Jobs post let me know.



There can be an issue with the NIC that you have and the flavor of Linux that you are using (I once spent two days just tracking down this issue). Try another NIC. Also it can be your ITSP try a different one and see what happens. In general cable has a lot more latency than DSL so you should be getting better results with the DSL. Another question, how many calls do you have going on at once ? Too many calls can be hogging your bandwidth.

As far as QoS goes I bought a cheap Linksys router and installed DD-WRT on it. It has great QoS on it.

Thanks for replying…

The on board 10/100 NIC is still in the machine so I can alway try that port again.

As far as ISP, I have a drop from both of the Highspeed Providers in my area (Comcast, Verizon).

If it was the NIC card wouldn’t the in-office calls has same issues?

For all my testing there has only been one line used unless I was trying to push it a little harder and I would use all 4 trunks I have available.


So with verizon and comcast you have the same issue ? I would try using a different ITSP (like teliax) and seeing what happens. It could be your ITSP.